Laser-induced forward transfer in picosecond regime for cell bioprinting
Based on interdisciplinary approaches, bioprinting methods aim to create and pattern highly organized 2D and 3D cultures. In that scope, it has been more than a decade since Laser-Induced Forward Transfer (LIFT) was studied on a lab scale for its ability to transfer biomaterials, specifically bio-ink loaded with living cells, on a substrate. Extreme physical and mechanical phenomena contribute to the jetting dynamic of the targeted bioink, raising a spontaneous biological question: does this process negatively affect the survival rate of transferred cells? This study demonstrates that laser pulse duration in the range of pico to nanoseconds does not directly affect cell viability, indicating that LIFT is a valuable bio-printing method to transfer living cells. Moreover, we highlight the necessity of using hydrogel coatings on the surface of the receiver substrate to guarantee optimal post-printing viability of the cells. We demonstrate that the nature of the hydrogel also contributes to the resolution of the printed pattern. From the tested materials, Matrigel demonstrated all the qualities required to ensure successful printing and is thus to be considered for future work. Overall, the results show the suitability of our LIFT setup for printing living cells in the picosecond regime with a high survival rate, paving the way for a wide range of biological applications.